The discovery of Carlin-type gold deposits in northeast Nevada reshaped the US gold mining industry and propelled two companies to the top of the global producer list. These deposits, named after the town of Carlin, are defined by microscopic gold locked in arsenic-rich pyrite. When Newmont began mining at Carlin in May 1965, it opened what was then the largest gold mine in the United States in half a century.
The origins of Carlin-type deposits
Evidence of what would later be recognised as Carlin mineralisation was noted as early as 1939. In 1954, American geologist Ralph Roberts mapped ore deposits in north-central Nevada, and he published his findings in a six-page report in 1960. That report became a key reference for Newmont and Barrick as they searched the Carlin trend for gold. Newmont stepped up staking and drilling in the early 1960s, establishing an initial reserve in 1963 and culminating in first production at the Carlin mine two years later.
At the time, Newmont's president said the Carlin mine would rank as the second-largest gold mine in the United States after Homestake, and the fourth-largest in North America. The operation ran as an open pit processing 2,000 tons of ore per day and producing 200,000 ounces annually over a projected life of more than a decade.
Newmont's growth from the Carlin trend
The original Carlin mine produced 3.8 million ounces of gold before it was idled in 1987. But the trend continued to yield discoveries. Through the 1980s and into the 1990s, further high-grade deposits were found along the same geological belt, including Gold Quarry, Rain, Genesis and Eureka. These new mines added substantial output and laid the foundation for Newmont's expansion into the world's largest gold producer.
Barrick's transformation via the Carlin trend
The Carlin trend also proved pivotal for Barrick. The company acquired the Goldstrike project in 1987 and went on to develop the Betze, Screamer and Rodeo deposits. Goldstrike alone produced 44.4 million ounces of gold until 2018, when the asset became part of the Nevada Gold Mines joint venture with Newmont. That joint venture now operates the combined land package, ensuring the Carlin trend remains a cornerstone of US gold output.
Key takeaways
- Carlin-type deposits are characterised by microscopic gold in arsenic-rich pyrite and were first identified in the 1960s.
- Newmont's Carlin mine began production in 1965 and produced 3.8 million ounces before being idled in 1987.
- Barrick's Goldstrike project on the Carlin trend produced 44.4 million ounces up to 2018.
- The Carlin trend helped both Newmont and Barrick become two of the world's largest gold producers.
Common questions
What are Carlin-type gold deposits?
Carlin-type deposits are gold deposits where the gold occurs as microscopic particles hosted in arsenic-rich pyrite. They are named after the town of Carlin in northeast Nevada, where the first mine of this type was developed.
Why are Carlin-type deposits important?
They have been a major source of gold in the United States and provided the production base that allowed Newmont and Barrick to grow into the world's leading gold mining companies. The deposits continue to be mined through the Nevada Gold Mines joint venture.
The Carlin trend's legacy is still visible in today's gold market. For those following the sector, the live gold price reflects the output from historic deposits such as these, which have helped supply the market for decades.